Cytochrome P4502E1 is a major drug metabolizing enzyme in human liver. It has been shown that single-dose disulfiram inhibits P4502E1 in humans. Although it has been shown that single-dose disulfiram is a highly effective inhibitor of P4502E1, the duration of inhibition is unknown. The purpose of this investigation is to determine the duration of inhibition of cytochrome P4502E1 following a single dose of disulfiram.